With advent of desktop computing during latter half of last century, printers have become ubiquitous as they provide means to transfer graphics or text generated or stored in digital form in the computing devices to a persistent human-readable representation on paper or similar physical media. Even though rapid penetration of internet during the current century has considerably reduced the need for printing as a means of moving documents, and simultaneous availability of wide variety of reliable digital storage systems has reduced need of a printed physical backup or printed offline reading material, printers are still required for special purposes, like printing photographs or artwork or legal and other documents which need to be presented in hard copies, and therefore, are essential equipment for any office. Continuously downward trend in cost of printers has made them affordable to be commonplace even for home applications for use as personal printers. As things stand today, conventional printers have been largely replaced by Multi-Functional Printers (MFPs) that are typically utilized for meeting scanning, printing, and copying needs of big and small entities or individuals.
MFPs typically print images by depositing toner (stocked in the printer in cartridges) on receivers (or imaging substrates), such as paper or other planar media, glass, fabric, metal, or other objects. They operate using toners of different colors such as cyan (C), magenta (M), yellow (Y), black (K), and other colorants. Events of any of these cartridges/toners getting exhausted are major reasons for interruption in working of MFPs as the printer stops giving prints of satisfactory quality. The printer may also be programmed to stop functioning as soon as any of the cartridges is exhausted. Therefore, economical consumption of toners can lead to fewer interruptions besides reducing printing cost on account of cost of cartridges.
As is evident, different documents/images require differing amounts of different toners depending on their composition leading to uneven usage of different toners. The un-even usage or varying rate of toner throughput causes some cartridges to run out faster than others, which leads to unplanned unavailability of printer or MFP equipment due to unavailability of certain toners. This also leads to frequent changing of cartridges for example next cartridge may need to be replaced in a relatively short amount of time after a previous one had just been replaced.
Therefore, MFPs remain down for undesirably long time due to running out of one or other toner sometimes merely for a single toner. Putting more technically, this problem arises on account of unequal throughput rates, which is amount of toner or ink being used/spent from each toner cartridge, for different toners during printing process. At a more micro-level, it is Toner Throughput Rate (TTR) that is manipulated or adjusted whenever a user actuates any of the provided modes (as illustrated by FIGS. 1, 2, and 3) of operation in conventional printers, albeit without linking the TTR to present level of respective toner in the cartridge.
There is therefore a need in the art for a MFP that overcomes above stated deficiencies of conventional MFPs.